The analysis of the changes in the path of the Kuroshio south of Japan has always been a hot topic.Previ-ous studies have pointed out that the changes in the Kuroshio path south of Japan are influenced by various factors,such as upstream transport,mesoscale eddies,climate signals etc.However,the causal relationship between these influencing factors is not fully understood.The paper first obtains the time series of the Kuroshio path south of Ja-pan based on the 50 year(1958-2007)China Ocean Reanalysis dataset(CORA)and 14 year(2008-2021)satellite altimeter data,and uses the Complex Empirical Orthogonal Function(CEOF)analysis method to analyze its spati-otemporal characteristics.The results show that the first two main modes obtained by CEOF analysis can describe the main characteristics of the space-time variation of the Kuroshio path in the south of Japan and represent the re-lated eastward and westward signals,respectively.Furthermore,the causal analysis results based on information flow theory indicate that:on the one hand,PDO affects the eddy kinetic energy in the subtropical countercurrent(STCC)region through changes in wind stress,thus affecting the changes of Kuroshio transport in the Tokara Strait,and then has a direct impact on the eastward signal,and finally affects the changes of the Kuroshio path in the southern region of Japan.On the other hand,the eddy kinetic energy of the Kuroshio extension is influenced by the NPGO signal,which affects the westward movement of the mesoscale eddies in the region,thereby directly af-fecting the westward signal and ultimately affecting the Kuroshio path changes in the region south of Japan.In addi-tion,the experimental results also indicate that the relative vorticity and recirculation gyre strength in the southern region of Japan are responses to the changes in the Kuroshio path,rather than factors affecting the changes in the Kuroshio path.
Kuroshio path south of JapanCEOFcausality analysisinformation flow
维普
万方数据
